The value of a stock averaged 45 last year. You decide to measure the hourly value of the stock over one day of trading last week. In the 8 hourly measurements the average value of the stock at beginning of each hour was 45.2 with a standard deviation of .15.

a) At the .01 level was the value of the stock statistically significantly different each hour than its typical average? (p = .007)

b) The 99% confidence interval is (45.01, 45.39) Interpret this in context of the problem

c) If tomorrow you decide to take 8 hourly measurements of the stock would an average of 47 be something you would expect? Explain

d) True or False: Natural Variability is the reason for the difference in the expected average and your sample average based on the answer for a)